As is known, an optical waveguide may be created by coupling electric fields into an electro-optic element, thereby locally increasing its refractive index to produce a waveguiding channel therein. Indeed, others have already proposed or developed fringe field and bulk field controlled branching electro-optic waveguides for steering and/or switching light beams. See, for example, U.S. Pat. No. 3,795,433, which issued Mar. 5, 1974 on "Voltage Induced Optical Waveguide Means," and Donald H. McMahon, "Multimode Optical Switching," Laser Focus, March 1979, p. 46 et seq.
IBulk field controlled electro-optic waveguides tend to suffer from a lack of structural strength because they usually comprise a thin electro-optic crystal (i.e., a crystal having a thickness of less than 100 microns or so) which is sandwiched between opposed electrodes. Fringe field controlled waveguides are likely to be sturdier, but branching waveguides of that type typically are relatively lossy devices because of discontinuities in the fringe fields and optical transformations of the guided light.